Inboard power unit for shallow draft boats



Oct. 2, 1951 J. w. DANIELS 2,569,302

INBOARD POWER UNIT FOR SHALL-OW DRAFT BOATS Filed Feb. 21, 1949 l 2 Sheet s-Sheet 1 J. w. DANIELS INBOARD POWER UNIT FOR SHALLOW DRAFT BOATS Filed Feb. 21, 1949 Oct. 2, 1951 2 Sheets-Sheet 2 Patented Oct. 2, 1951 OFFICE INBOARD POWER UNIT F( R SHALLOW DRAFT BOATS James W. Daniels, Fort Myers, Fla. Application February 21, 1949, Serial No. 77,645

9 Claims.

This invention relates to shallow draft boats and more particularly to an inboard power unit therefor which is constructed and arranged so that parts of the unit projecting below the hull, particularly the propeller, are automatically withdrawn within the contour of the hull in case the boat runs into very shallow water or over a sand bar, rock, or other obstruction to navigation.

An object of the invention is to provide a simple and inexpensive power unit of the above type whichv is easy to install in the boat and automatic and reliable in its operation.

Another object is to provide for automatic withdrawal of the propeller and associated parts within a well while maintaining the desired fairing of the hull inxnormal'running and for a power plant outside the well where .it is easily. accessible at alltimes for starting, servicing, and like purposes.

A further object is to provide a power unit of the kind characterized above wherein withdrawal of the propeller and associated parts into the well does not interfere with the normal utilization of the space within the boat.

Astill further object is to provide a power unit of the type characterized in the preceding objects which comprises a unitary assemblage of power plant, drive shaft, propeller, rudder, steering mechanism and fueltank that is installable in. or removable from the boat as .a unit.

One embodiment of the invention has been illustrated in the accompanying drawings, but it is .to be expressly understood that said drawings are for purposes of illustration only and are not to be taken as a definition of the limits of the invention, reference being had to the appended claims for this purpose.

.In thedrawings,

.Fig. l is a plan view of a shallow draft boat embodying the invention;

,Fig. 2 is a side view of the boat with the near side removed to show the interior;

Fig. 3 is an enlarged detail, partly in section, showing the power unit in normal position;

Fig. 4 is asimilar enlarged detail showing the propeller and associated parts withdrawn into the'hull; and r Figs. 5 ands are'dfetailsections of the steering shaft and the filling tube for the fuel tank.

The invention is particularly applicable to small'flat-bottomed :boats and hence it can be illustrated and "described conveniently in connection therewithrralthough its use is not restricted. to this application. The drawings show 2 a typical boat of this type, comp ng a flat o tom I and sides 2, a pointed bow 3 angle square sternwi, and a thwart 5 and small bow and stem decks 6 and 7, respectively.

An opening of suitable size and shape, preferably rectangular and elongated in the fore and aft direction, is formed in thebottom I nearthe stern of the boat and is framed by vertical side walls 8 and forward and aft .end walls .9 and II] to form an open well, the walls being of course high enough to extend above the waterline. The well will usually be built permanently into the boat structure except that the forward wall 8 or a portion thereofis preferably removable to facilitate removal of the power unit from the boat. In the form shown, this forward wall comprises a metal plate the lower edge of which issecured to a transverse. member II at .theforward edge of the well and the sides of which are bent around the walls 8 of the well as indicated at I2 in Fig. 2 and suitably secured thereto.

The inboard power unit per se comprises a supporting frame having two sections united by an upwardly extending, U-shaped frame member or members to form a rigid structure. The after support section comprises a plate-like bottom member I3 forming a bottom closure for the .well in normal running position and shaped to maintain the desired fairing of the hull. In the present case, therefore, the member I3 has a flat bottom, and in its normal position in the well (Figs. 2 and 3) the end of the support rests on a stop plate I 4 so that itis flush with the flat bottom I of the boat. The forward .Support section comprises a bed I5 for mounting a suitable power plant, here shownas an air-cooled internal combustion engine I 6. The two support sections are rigidly united by .U -shaped frame members I! which may be connected by any, suitable number of transverse brace bars I8. Whenthe unit is installed in the boat, the frame members I! straddle the forward end wall 9 of the well, the

after or rear support section I3 being located in the well as described above, and the forward bed section 15 being outside the well and near the bottom of the boat where the engine I6 is out of the way as much as possible and the stability of the boat isincreased while the engine is easily accessible at any time for starting or service.

The power plant {6 drives a shaft I9 anda-propeller 2?; mounted on the end of the drive shaft beneath the after support section I3, A tubular bearing 2| for the drive shaft extends downwardly at anangle through the support I 3, to which it is suitab y secured as y weldin and 3 the upper forward end of this bearing projects freely through an opening in the forward end wall 9 of the well and terminates close to the power plant. Thus a large part of the length of the drive shaft i9 is supported and enclosed in the bearing, and leakage of water between the shaft and bearing is easily prevented by suitable packing and nuts 22 at one or both ends of the bearing. A flexible seal 52 of any suitable type surrounds the shaft bearing 2| and is secured to the end wall 9 of the well to prevent leakage of water through the opening through which the a bearing passes in case the water in the well should rise to this level.

The rig-id supporting frame l3, l1, I is pivotally mounted as a unit so that the after support section 13 can swing between the positions shown in Figs. 3 and 4. By locating the pivot axis close to the forward end of the well between the two support sections, the entire unit is substantially counterbalanced, and a slight upward force on the support i3 is sufficient to swing it to the posi- 'tion shown in Fig. 4. Also the pivot axis is preferably located as near as possible to the shaft bearing 2! so as to minimize the movement of the bearing in the opening in the end wall 9. In the form shown, bearing brackets 23 project rearwardly from the forward vertical legs of the frame members I'I just below the shaft l9 and its tubular bearing 2!, and corresponding brackets 24 extend forwardly from the sides of the well, the unit being pivotally mounted by a pin 25 extending through these brackets.

In case the boat runs into very shallow water or passes over an obstruction such as a sand bar or rock, the entire unit therefore swings easily on the axis 25 to tilt the support 53 to the position shown in Fig. 4 and withdraw the propeller into the well where it will not be damaged.

This tilting movement takes place automatically by virtue of a suitable keel-like guard projecting below the support l3 in advance of the propeller 2i). In the form shown, a strut 26 extends from the forward end of the support It parallel to and beneath or in advance of the drive shaft. The end of this guard is connected to the support I3 by a vertical strut 21 which can be utilized to provide a further shaft bearing 28.

The unit may also be tilted manually and held in the position shown in Fig. 4 whenever desired,

and it is advantageous to provide a simple manually operable means to tilt the unit and to hold or look it in tilted position. In the form shown,

4 to provide the proper location of the propeller, need project only slightly if at all above the level of the stern deck, and most of the length of the well can also be closed by a suitable removable cover 33 as indicated in Fig. 4 so as to preserve a maximum of utilizable boat space without interference from the tilting frame and associated a tube 29 is secured to the frame members I! above the top of, the well and a shaft 3!] is rotatable in the tube by means of a handle 3|. The shaft carries eccentrics 32 which engage the top edges of the side walls 8 of the well. When the handle is in the position shown in Figs. 1 and 2, the eccentrics permit the rear support section E3 to rest on the stop plate M as shown in Figs. 2 and 3, and to swing freely and automatically between the positions shown in Figs. 3 and 4. When the handle is swung counterclockwise, however, the eccentrics are rotated to the position shown in Fig. 4 with the result that the unit is tilted and locked in tilted position.

In order to provide a complete self-contained power unit, the rear support section i3 is utilized to carry suitable steering gear and a fuel supply tank. On the other hand, these parts are so arranged that even when the unit is tilted, they do not project above the top of the well exwell, which is' set well back into the stern deck 1 parts. Fig. 4 shows the position of maximum tilt of the frame in which the extreme rear end of the support i3 is at a level just below the top of the well. The support being inclined, however, its forward end is only slightly elevated above the bottom of the well. The solid angle between the inclined support and a horizontal plane through its elevated rear end is therefore available for fuel tank, steering mechanism, and the like, with the result that the unit per se comprises a rear section which tapers in general outline from its forward to its rear end.

Thus the forward part of the rear frame section comprises a wedge-shaped fuel tank either mounted on the support is or built up in any suitable manner using the support itself as the bottom of the tank. For example, a vertical wall 34 extends upwardly from the forward end of the support to form the end of the tank, and its sides are formed by vertical walls 35 along the side edges of the support, the walls 35 decreasing in height toward the rear for the reason explained above. The top of the tank is formed by a plate 35 extending between and joined to the side walls 35. The shaft bearing 2| extends down through the tank, the forward part of the plate 35 preferably extending over the top of the shaft bearing as shown in Fig. 4 and its end being joined to the end wall 34. The rear end of the tank is formed by a vertical Wall 3? provided with a drain plug- 38, this rear end wall being located short of the rear end of the support l3. The tank is filled through a suitable filling cap 39 which for convenience can be located on the steering apparatus above the top of the well as described below.

A suitable rudder 4% is mounted below the rear end of the support 33 behind the propeller 20. The lower pintle 4! of the rudder turns in a bearing formed in the end of an extension 42 of the strut 25, which also passes under the propeller 2B .and further protects it against damage. The upper rudder pintle 43 extends rotatably through a bearing 44 in the rear end of the support l3- so that the rudder can be operated from above the support. For reasons set forth above, however, the rudder actuating member projects above the top of the well near its forward end and is connected to the rudder through suitable operatingmechanism. In the form shown, a steering wheel 45 and its approximately vertical shaft 46 are rotatably mounted on a spindle 41, preferably tubular, which projects upwardly from the top of the fuel tank, and an arm 48 on the ower end of the shaft is connected by a link 49 with an arm '50 connected to the upper end of the rudder pintle 43. In case the axes of the shaft 46 and rudder pintle 43 are not parallel, a ball joint 5| can be used to connect the arm 48 and link 49.

The spindle 41 is preferably tubular to provide a convenient means for filling the tank from a point above the top of the well. In the form shown, the tubular base of the spindle delivers fuel to the tank through an opening 52 in the top plate 36. The steering shaft surrounds and rotates on the spindle between a shoulder 53 and nut 54. The upper end of the tubular spindle is closed by the filling cap 39 mentioned above.

It will be understood that the unit is desirassures position-of F gs; 2 and 3 in ismay be cone by providnormalrunning stalled iii or removed fromthe" boat as a complete, integral "unit. Whenin alled in the boat, however, the invention providessubstantially all the advantage's'of' 'a"perm nently built-in installation. That is, the eiigihiormotor has api proximately the usual location where it is readily accessible at any time, t-he propeller is "properly located beneath and Well to therear of the boat,

cavitation effects are eliminated and the normal hull contour is unchanged during normal running, and the drive shaft, fuel tank, and steering gear are substantially enclosed so that they are protected against damage and so that danger to the occupants of the boat is minimized at the same time. In addition, the tilting movement of the unit automatically protects the propeller and rudder against damage in case of shallow obstructions, while the engine continues to run and the normal propelling action is resumed as soon as the boat passes over the obstruction. lhis action takes place without interfering with or in any way altering the use of the boat space, and in fact is scarcely noticeable to occupants of the boat except for a small amount of displacement of the steering wheel.

While only one embodiment has been described and illustrated in the drawings, it will be understood that the invention is susceptible of other embodiments and that various changes may be made in the details of construction and arrange r ment of the parts without departing from its spirit. Moreover, any suitable type of engine can be used, including any desired type of drive as respects gearing, clutching, and like mechanical details. appended claims for a definition of the limits of the invention.

What is claimed is:

1. A boat having a well in its bottom, a platelike support forming a closure for the bottom of the well and maintaining the normal hull contour, said support having an extension over the forward end of the well and down outside the well toward the bottom of the boat, a power plant carried by said extension, a tubular shaft bearing extending downwardly at an angle through and secured to said plate-like support with its forward upper end projecting movably through an opening in the forward end of the well, flexible sealing means between said tubular bearing and the end of the well, a drive shaft extending from said power plant through said shaft bearing, and a propeller on the end of said drive shaft, said support and extension being pivoted outside the well on an axis between the forward end of the well and the power plant whereby said support is tiltable in the well to withdraw said propeller therein, the forward part of said support carrying a wedge-shaped fuel tank, the top of said tank being inclined rearwardly toward said sup- Hence reference should be had to the 531 "forward end of" the" extending downwardly at n 6 pert-au t {it (if the tani atafnypointbe n "no greater nthe yer 1 distance tea ee'n the tilted 1 "suppoi rear end, the eiev greater than ftl 2. "The con v and the level er its elevated *o'fjthewell. p, n define in claim lj-"said {tubular shaft tearing *e'iitnuing through said.

w fie m 3. Aboathavi ng dwell itsbottbih, platefke support form g a closure'mr the 'bo'ttiom of the war and "ma n in ng tne' ormar hull eb ntour, said support haying an "extension "over "the well and down outside "the mo 11' n owemtne a bular shaftbearmg secured to said} plate-like support with its ward u per end roi ctingfmovalily through an binning in the oiwar en er, t e wen, flexible sealing Thea t'wee propelleronthe'errd10f said dr1ve shaft, a read r mounted on and beneath the reefer said su port and having an operating shaft extending through said support, a rudder-actuating member extending upwardly from the forward end of said support above the top of the well, and rudder-operating means connecting the lower end of said member with the upper end of said shaft, said support and extension being pivoted outside the well on an axis between the forward end of the well and the power plant whereby said support is tiltable in the well to withdraw said propeller and rudder therein.

4.. An inboard power unit for a shallow draft boat provided with a well, said unit comprising a frame having a rear well section and a forward bed section, said sections being rigidly connected by a U-shaped frame section extending upwardly therefrom, a power plant mounted on said bed section, a. tubular shaft bearing extending downwardly at an angle through and secured to said rear section, the forward upper end of said tubular bearing being close to said power plant, a drive shaft extending from said power plant through said bearing, a propeller on the end of said drive shaft, a rudder mounted on and beneath the rear end of said rear section behind the propeller and having an operating shaft extending through said support, rudder-operating mechanism including an actuating member extending upwardly from the forward end of said rear section, a guard projecting downwardly from said rear section in advance of said drive shaft and propeller, and means for pivoting the unit on an axis between said rear and bed sections comprising a bearing bracket mounted on said U-shaped frame section.

5. The unit defined in claim 4, including manually rotatable eccentric means mounted on the upper part of said U-shaped frame section to the rear of said bearing lug, whereby the unit may be tilted manually around the axis of said 1 bracket when installed in the boat.

6. The unit defined in claim 4, the forward part of said rear section carrying a wedge-shaped fuel tank having a top inclined rearwardly and downwardly toward said rear section, said tubular bearing extending through said tank and said rudder-actuating member extending upwardly above the tank.

7. The unit defined in claim 6, said rudderactuating member being tubular, and means for feeding fuel therethrough for filling the tank.

t'lon df "saidrearend being angle mrougii e e.

'8. A boat having a well in its bottom which is elongated in a fore and aft direction, and an inboard power unit comprising a frame having a rear well section and a forward bed section, said sections being rigidly connected by a U-shaped frame section straddling the forward end of the well, a power plant mounted on said bed section, a propeller, rudder and fuel tank carried by said rear section, propeller driving means including a shaft driven by said power plant and extending through an opening in the forward end of the well, rudder-operating mechanism carried by said rear section and including an actuating member projecting above the top of the well near its forward end, pivot means for said unit having a transverse axis located outside the well adjacent its forward end and between said rear and forward sections, whereby said unit may be 8 eluding a transverse, manually rotatable shaft secured to said U-shaped frame section above the top of the well, and an eccentric member rotatable by said shaft and' engaging the top of the well to tilt said unit. 7

' JAMES W. DANIELS.

REFERENCES CITED The following references are of record inthe file of this-patent:

V UNITED STATES PATENTS Number Name Date 130,110 Dodge Aug. 6, 1872 149,969 Atkinson Apr. 21, 1874 695,717 Gardiner Mar. 18, 1902 1,490,046 Turnbull Apr. 8, 1924 1,850,770 Ramsey Mar. 22, 1932 2,096,223 Chandler Oct. 19, 1937 FOREIGN PATENTS Number Country Date 181,959 Great Britain June 29, 1922 410,400 Germany 1 Mar. 6, 1925 

